• Title/Summary/Keyword: High school laboratory

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New PDP cell structure for high luminous efficacy with low voltage driving

  • Jung, Hae-Yoon;Kim, Tae-Jun;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.480-484
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    • 2006
  • We propose a new PDP cell structure named DIDE (Dual Ignition Discharge Electrodes) structure with a long electrode gap to realize a high luminous efficacy. Suggested DIDE structure basically has a long electrode gap $(200{\mu}m{\sim}400{\mu}m)$, nevertheless, because of auxiliary electrodes formed on the front panel, can be driven at relatively low voltage. The discharge characteristic of DIDE structure was much different from that of conventional structure, which was analyzed by IR emission images using IICCD (Image Intensified Charge Coupled Device). The study can explain some particular characteristics of DIDE structure. As a result, the long electrode gap and low voltage effect can be expected in DIDE structure, and a very high luminous efficacy of 7.5 lm/W has been achieved in monochrome green test panel adopting the new cell structure with Ne-Xe (12%) mixture at 400 torr.

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Highly Enantioselective Addition of Diethylzinc to Aldehydes Catalyzed by Novel Chiral tert-Amino Alcohols

  • Zhang, Cong-Hai;Yan, Sheng-Jiao;Pan, Sheng-Qiang;Huang, Rong;Lin, Jun
    • Bulletin of the Korean Chemical Society
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    • v.31 no.4
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    • pp.869-873
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    • 2010
  • A series of novel chiral tert-amino alcohols 4a-h derived from enantiomerically pure phenylalanine were synthesized efficiently and used as chiral ligands in the catalytic enantioselective ethylation of aldehydes with diethylzinc (diethylzinc-to-aldehyde addition). The use of 10 mol % of the amino alcohols led to the corresponding sec-alcohols with excellent enantioselectivities (up to 100% ee) and high yields.

A dryout mechanism model for rectangular narrow channels at high pressure conditions

  • Song, Gongle;Liang, Yu;Sun, Rulei;Zhang, Dalin;Deng, Jian;Su, G.H.;Tian, Wenxi;Qiu, Suizheng
    • Nuclear Engineering and Technology
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    • v.52 no.10
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    • pp.2196-2203
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    • 2020
  • A dryout mechanism model for rectangular narrow channels at high pressure conditions is developed by assuming that the Kelvin-Helmholtz instability triggered the occurrence of dryout. This model combines the advantages of theoretical analysis and empirical correlation. The unknown coefficients in the theoretical derivation are supported by the experimental data. Meanwhile, the decisive restriction of the experimental conditions on the applicability of the empirical correlation is avoided. The expression of vapor phase velocity at the time of dryout is derived, and the empirical correlation of liquid film thickness is introduced. Since the CHF value obtained from the liquid film thickness should be the same as the value obtained from the Kelvin-Helmholtz critical stability under the same condition, the convergent CHF value is obtained by iteratively calculating. Comparing with the experimental data under the pressure of 6.89-13.79 MPa, the average error of the model is -15.4% with the 95% confidence interval [-20.5%, -10.4%]. And the pressure has a decisive influence on the prediction accuracy of this model. Compared with the existing dryout code, the calculation speed of this model is faster, and the calculation accuracy is improved. This model, with great portability, could be applied to different objects and working conditions by changing the expression of the vapor phase velocity when the dryout phenomenon is triggered and the calculation formula of the liquid film.

Generation of High Resolution DEM of Jeju Island

  • Lee, Chang-Won;Kim, Duk-Jin;Moon, Wooil M.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.831-833
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    • 2003
  • We have evaluated the accuracy of digital elevation models of Jeju island generated with three different sensors, NASA JPL TOPSAR, JERS-1 SAR, KOMPSAT-1 EOC using Interferometric SAR and stereo photogrammetry. Characteristics and limitations of each method are described.

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Production of Chemistry Laboratory Class for Senior High School Freshmen

  • Yasuzawa, Mikito;Minagawa, Keiji;Kamitani, Sachiyo;Arai, Yuka;Konishi, Yuki;Nakanishi, Shinsuke;Oshima, Takuya;Yamaguchi, Junko;Ishii, Arisa
    • Journal of Engineering Education Research
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    • v.13 no.5
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    • pp.55-60
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    • 2010
  • Chemistry laboratory class was produced for senior high school freshmen with the cooperation of university staffs, high school teachers and the university students. Although the students who will take the lab class are senior high school freshmen, we decided to prepare four experiments that are simple and have highly visible reactions or transformation. That is, 1) Water purification, 2) Surface modification, 3) Briggs-Rauscher reaction, and 4) Polymer synthesis and characterization. After the safety guideline and experiment instructions by the faculty staffs, two teaching assistants (TAs) supervised each experiment. Since taking a direct part in it will provide stronger impact than only being one who is just watching the experiment, all experiments contained some process that the high school students must handle the reagents, tools or the equipment, by themselves. Although, the operation performed by the students was limited to a series of simple actions, the various unique phenomena presented by the experiments impressed the students. The lab class was fruitful not only for high school students, but also good for university students. The lab class provided good opportunity for them to improve the abilities to teach and guide someone.

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Desalting of tobacco extract using electrodialysis

  • Ge, Shaolin;Li, Wei;Zhang, Zhao;Li, Chuanrun;Wang, Yaoming
    • Membrane and Water Treatment
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    • v.7 no.4
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    • pp.341-353
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    • 2016
  • Papermaking reconstituted tobacco is an important strategy for recycling the waste tobacco residues. To indentify the influences of the inorganic components on harmful components delivery in cigarette smoke, a self-made electrodialysis stack was assembled to desalt the tobacco extract. The influences of the applied current and extract content on the removal rate of the inorganic ions were investigated. Results indicated that the applied current was a dominant impact on the desalination performance. High currents lower than the limiting current density could accelerate the desalting efficiency but cause higher energy consumption. A current of 2 A, or current density of ${\sim}11mA{\cdot}cm^{-2}$, was an optimal choice by considering both the energy consumption and desalting efficiency. A 20% tobacco extract was an appropriate content for the electrodialysis process. More than 90% of inorganic ions could be removed under the optimum condition. The preliminary result indicated that removal of inorganic components was beneficial to decrease the harmful component delivery in cigarette smoke. Naturally, ED is an environmentally friendly and high-effective technology for desalting the tobacco extract.

Deep Local Multi-level Feature Aggregation Based High-speed Train Image Matching

  • Li, Jun;Li, Xiang;Wei, Yifei;Wang, Xiaojun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.5
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    • pp.1597-1610
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    • 2022
  • At present, the main method of high-speed train chassis detection is using computer vision technology to extract keypoints from two related chassis images firstly, then matching these keypoints to find the pixel-level correspondence between these two images, finally, detection and other steps are performed. The quality and accuracy of image matching are very important for subsequent defect detection. Current traditional matching methods are difficult to meet the actual requirements for the generalization of complex scenes such as weather, illumination, and seasonal changes. Therefore, it is of great significance to study the high-speed train image matching method based on deep learning. This paper establishes a high-speed train chassis image matching dataset, including random perspective changes and optical distortion, to simulate the changes in the actual working environment of the high-speed rail system as much as possible. This work designs a convolutional neural network to intensively extract keypoints, so as to alleviate the problems of current methods. With multi-level features, on the one hand, the network restores low-level details, thereby improving the localization accuracy of keypoints, on the other hand, the network can generate robust keypoint descriptors. Detailed experiments show the huge improvement of the proposed network over traditional methods.

A Study on the Educational Environment Composition for High School Equalization Policy - Focused on the Space Composition and Distribution of Departmentalized Classroom System in High School in Kangwon-Do based on rural village - (고교 평준화를 위한 교육환경 구성에 관한 연구 - 농촌기반 강원도내 교과교실제 운영 고등학교의 공간 구성 및 면적분포를 중심으로-)

  • Kim, Hak Cheol
    • Journal of the Korean Institute of Rural Architecture
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    • v.17 no.4
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    • pp.83-90
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    • 2015
  • The equalization policy needs various factors-standardization of educational environment, standardization of learning method, standardization of teacher ability, etc. Especially the standardization of educational environment is the base of various factors. But the recent educational environment condition of high school is not equal. The purpose of this study is to provide basic data for equal learning environment condition in high school applying departmentalized classroom system. This study has progressed through analyzing on 9 remodelling case of high school in Gangwon-Do. The method of this study is visiting high schools that operate the system, grasping the condition for environment composition, and investigating and analyzing practical use of the environment. The results of this study are summarized as follows: 1) The space compositions for departmentalized classroom system are generally desirable, but some schools take irrational space composition, especially on home base-teacher laboratory, classroom-teacher laboratory. 2) The space area distributions are different in every school. This result is based on not taking standard criterion on space area distribution.